Oral Care Compositions With Improved Rheology

ABSTRACT

A dentifrice composition containing a polyethylene glycol having an average molecular weight of from about 3,000 to about 8,000, glycerin, precipitated silica, and a fluoride source. The polyethylene glycol forms a crystalline structure in the composition and the composition has a water activity from about 0.25 to about 0.46 measured at about 22° C.

FIELD OF THE INVENTION

The present invention relates to topical compositions, such as oral carecompositions, having improved rheology containing humectants such aspolyethylene glycol.

BACKGROUND OF THE INVENTION

Traditionally, much effort has been expended to balance a number ofimportant consumer-related factors in an oral care composition, such asa dentifrice. Because of the nature of such compositions, consumers havecome to expect a variety of efficacy benefits such as cleaning,whitening, gum health, and the like. However, since the compositions aretypically used in the mouth and are delivered by use of a toothbrush,additional care must be given to viscosity, rheology, mouth feel andtaste as these are also important to consumers. A particular consumerconcern is that a composition not be too runny or too thick but willfairly easily dispense out of a tube or other packaging and then sit ontop of the toothbrush bristles. Efforts to improve these attributes aretherefore common in the art, with varying success.

Cleaning abrasives such as silicas, (for example cleaning precipitatedsilicas) have been used in dentifrice compositions to mechanically cleanthe tooth surface.

Humectants such as polyethylene glycols have been used in dentifricecompositions to modify viscosity and to provide a smooth feel todentifrice compositions. Polyethylene glycols are available in a largerange of average molecular weights and have different propertiesdepending upon their average molecular weights.

Despite the wide array of dentifrice products currently available, aneed still exists for a composition that can provide good cleaning andefficacy while delivering good rheology and viscosity to improve theconsumer use experience.

SUMMARY OF THE INVENTION

A topical composition is provided that comprises humectant componentfrom about 40% to about 77% by weight of the composition, wherein thehumectant component comprises from about 0.25% to about 7% by weight ofthe composition, of a structuring humectant selected from polyethyleneglycols having an average molecular weight of from about 3,000 to about8,000, and mixtures thereof; and at least one secondary humectant; thetopical composition further comprises abrasive from about 5% to about35% by weight of the composition; from about 0% to about 1.5% by weightof the composition, of a viscosity modifier selected from gums, binders,cellulosic thickeners, and mixtures thereof; a total solids content of50% or less by weight of the composition; water from about 5% to about12% by weight of the composition; and wherein the structuring humectantis added to the composition in solution with solvent or is added in acontrolled manner as a molten material to the composition at atemperature less than about 35° C. and with turbulent mixing or vigorousagitation.

An oral care composition is provided that comprises humectant componentfrom about 40% to about 77% by weight of the composition, wherein thehumectant component comprises structuring humectant from about 0.25% toabout 7%, by weight of the composition, selected from polyethyleneglycols having an average molecular weight of from about 3,000 to about8,000, and mixtures thereof; and at least one secondary humectant; theoral care composition further comprises fluoride from about 50 ppm toabout 3500 ppm; from about 0% to about 1.5% by weight of the compositionof a viscosity modifier selected from gums, binders, cellulosicthickeners, and mixtures thereof; from about 5% to about 35% by weightof the composition of an abrasive; surfactant from about 0.025% to about9% by weight of the composition; a total solids content of 50% or lessby weight of the composition; and water from about 5% to about 12% byweight of the composition; and wherein the composition comprises a wateractivity value of from about 0.25 to about 0.46 measured at about 22°C.; and wherein the structuring humectant is added to the composition insolution with solvent or is added in a controlled manner as a moltenmaterial to the composition at a temperature less than about 35° C. andwith turbulent mixing or vigorous agitation.

DETAILED DESCRIPTION OF THE INVENTION

It has now been surprisingly found that a non-anhydrous yet low waterdentifrice composition containing cleaning silicas, may be internallystructured by regulating the composition's level of water activity andincorporating a structuring humectant.

Active and other ingredients useful herein may be categorized ordescribed herein by their cosmetic and/or therapeutic benefit or theirpostulated mode of action or function. However, it is to be understoodthat the active and other ingredients useful herein can, in someinstances, provide more than one cosmetic and/or therapeutic benefit orfunction or operate via more than one mode of action. Therefore,classifications herein are made for the sake of convenience and are notintended to limit an ingredient to the particularly stated function(s)or activities listed.

These elements will be discussed in more detail below.

All percentages and ratios used hereinafter are by weight of totalcomposition, unless otherwise indicated. All percentages, ratios, andlevels of ingredients referred to herein are based on the actual amountof the ingredient, and do not include solvents, fillers, or othermaterials with which the ingredient may be combined as a commerciallyavailable product, unless otherwise indicated.

All measurements referred to herein are made at 22° C. (i.e. roomtemperature) unless otherwise specified.

As used herein, the word “about” means+/−10 percent.

As used herein, the word “include,” and its variants, are intended to benon-limiting, such that recitation of items in a list is not to theexclusion of other like items that may also be useful in the materials,compositions, devices, and methods of this invention.

These elements will be discussed in more detail below.

The compositions herein are useful for topical application. In oneembodiment, the composition is an oral care composition.

As used herein, “oral care composition” is meant a product, which in theordinary course of usage, is not intentionally swallowed for purposes ofsystemic administration of particular therapeutic agents, but is ratherretained in the oral cavity for a time sufficient to contactsubstantially all of the dental surfaces and/or oral tissues forpurposes of oral activity. The oral care composition may be in variousforms including toothpaste, dentifrice, tooth gel, subgingival gel,mouthrinse, mousse, foam, mouthspray, lozenge, chewable tablet, chewinggum or denture product. In one embodiment, the oral care composition isin a form selected from toothpaste, dentifrice, tooth gel, mouth rinseor denture product. The oral care composition may also be incorporatedonto strips or films for direct application or attachment to oralsurfaces.

The term “dentifrice”, as used herein, includes paste, gel, or liquidformulations unless otherwise specified. The dentifrice can be in a dualphase form, like a striped paste for example, and can also be used as aregimen.

The term “teeth”, as used herein, refers to natural teeth as well asartificial teeth or dental prosthesis and is construed to include onetooth or multiple teeth.

The compositions herein contain from about 40% to about 77%, by weightof the composition, of a humectant component. In one embodiment, thecompositions herein contain from about 45% to about 67%, by weight ofthe composition, alternatively from about 45% to about 62% of thehumectant component.

The humectant component contains a structuring humectant and at leastone secondary humectant.

The composition contains from about 0.25% to about 7%, by weight of thecomposition, of the structuring humectant. In one embodiment, thecomposition contains from about 0.5% to about 4%, by weight of thecomposition, of the structuring humectant.

The structuring humectant is selected from polyethylene glycols havingan average molecular weight of from about 3,000 to about 8,000, andmixtures thereof. In one embodiment, the structuring humectant isselected from polyethylene glycols having an average molecular weight offrom about 3,000 to about 6,000, alternatively from about 3,500 to about5,500.

Polyethylene glycol materials having an average molecular weight of fromabout 3,000 to about 8,000 are commercially available from suchsuppliers as Dow Chemical and BASF (New Jersey, USA). Examples ofcommercially available polyethylene glycol materials useful hereininclude PEG 4000 PLURIOL E 4000 Pastille and PEG 8000 PLURIOL E 8000 NFPrill having an average molecular weight of 4000 and 8000, respectivelycommercially available from BASF (Florham Park, N.J., USA).

Without being limited by theory, in order to ensure a structuringcrystalline structure is created in the composition, the structuringhumectant is added to the composition in solution with solvent (e.g,water) or is added in a controlled manner as a molten material to thecomposition, in certain embodiments with the temperature less than about35° C. and with turbulent mixing or vigorous agitation.

The humectant component contains at least one secondary humectant. Thesecondary humectant is selected from glycerin, glycerols, sorbitol,polypropylene glycol, low molecular weight polyethylene glycols, ediblepolyhydric alcohols, and mixtures thereof. In one embodiment, thesecondary humectant is selected from glycerin, sorbitol and lowmolecular weight polyethylene glycols

The compositions herein may further include from about 50 ppm to about3500 ppm of fluoride, wherein the fluoride is selected from stannousfluoride, sodium fluoride, sodium monofluorophosphate, and mixturesthereof. In one embodiment, the fluoride is selected from sodiumfluoride, stannous fluoride, and mixtures thereof, in another embodimentthe fluoride is stannous fluoride.

In one embodiment, the composition contains from about 650 ppm to about1500 ppm, alternatively from about 900 ppm to about 1300 ppm offluoride.

In one embodiment, the fluoride is present in the oral care compositionin an amount sufficient to give a fluoride ion concentration in thecomposition of from about 0.0025% to about 5.0% by weight to provideanticaries effectiveness. In one embodiment, the fluoride concentrationis from about 0.005% to about 2.0% by weight. A wide variety of fluorideion-yielding materials can be employed as sources of soluble fluoride inthe present compositions and methods. Examples of suitable fluorideion-yielding materials are found in U.S. Pat. No. 3,535,421 to Briner etal. and U.S. Pat. No. 3,678,154 to Widder et al. Representative fluorideion sources include: stannous fluoride, sodium fluoride, potassiumfluoride, amine fluoride, sodium monofluorophosphate, indium fluoride,amine fluorides such as Olaflur, and mixtures thereof.

The compositions herein may contain from about 0% to about 1.5%, byweight of the composition, of a viscosity modifier selected from gums,binders, cellulosic thickeners, and mixtures thereof.

The compositions herein may contain from about 5% to about 35%, byweight of the composition, of an abrasive. In one embodiment, theabrasive is selected from fused silica, precipitated silica, andmixtures thereof. In one embodiment, the composition contains from about10% to about 35%, alternatively from about 15% to about 35%,alternatively from about 15% to about 30%, by weight of the composition,of the abrasive.

In one embodiment, the abrasive is a precipitated silica. In oneembodiment, the abrasive is precipitated silica having an oil absorptionof less than about 250 cc/100 g, a BET surface area of less than about150 m2/g, and a median particle size of less than about 50 microns. Inanother embodiment, the precipitated silica has a particle size of fromabout 5 to about 20 microns. Abrasive precipitated silicas arecommercially available from Huber under the tradename ZEODENT (Havre deGrace, Md., USA).

Additional abrasives such as fumed silica, pumice, bioactive glass, andmixtures thereof may also be used in small amounts. The abrasivecontemplated for use in the compositions of the present invention can beany material that does not excessively abrade dentin. Typical abrasivesinclude silicas including gels and precipitates; aluminas; phosphatesincluding orthophosphates, polymetaphosphates, and pyrophosphates; andmixtures thereof. Specific examples include dicalcium orthophosphatedihydrate, calcium pyrophosphate, tricalcium phosphate, calciumpolymetaphosphate, insoluble sodium polymetaphosphate, hydrated alumina,beta calcium pyrophosphate, calcium carbonate, and resinous abrasivematerials such as particulate condensation products of urea andformaldehyde, and others such as disclosed by Cooley et al in U.S. Pat.No. 3,070,510, issued Dec. 25, 1962. In one embodiment, the dentifricecomprises a polyphosphate having an average chain length of about 4 ormore and is substantially free of calcium-containing abrasives andalumina.

In certain embodiments, the composition comprises less than 5%, byweight of the composition, of silica gels. In one embodiment, thecomposition comprises less than about 5%, by weight of the composition,of a thickening silica, alternatively less than about 2%, alternativelyless than 1%, by weight of the composition, of a thickening silica.

Silica gels include, for example, the silica xerogels described in Paderet al., U.S. Pat. No. 3,538,230, issued Mar. 2, 1970. Silica gels arecommercially available and marketed under the trade name SYLOID by theW.R. Grace & Company, Davison Chemical Division.

Without being limited by theory, it is believed that the low watercompositions herein enable the use of a single abrasive in addition toallowing for the use of smaller amounts of abrasives in combination withprecipitated and/or fused silica.

In certain embodiments, the abrasive is a silica having an averageparticle size ranging between about 0.1 to about 30 microns, andpreferably from about 5 to about 15 microns. Types of silica dentalabrasives useful in the toothpastes of the present invention aredescribed in more detail in Wason, U.S. Pat. No. 4,340,583, issued Jul.29, 1982. Silica abrasives are also described in Rice, U.S. Pat. Nos.5,589,160; 5,603,920; 5,651,958; 5,658,553; and 5,716,601. In oneembodiment, the abrasive in the toothpaste compositions described hereinis present at a level of from about 6% to about 70% by weight of thecomposition.

The present invention may include a polymeric anti-tartar, anti-stainagent. A polymeric anti-tartar, anti-stain agent may be a polyphosphate.A polyphosphate is generally understood to consist of two or morephosphate molecules arranged primarily in a linear configuration,however some cyclic derivatives may be present. Although pyrophosphatesand tripolyphosphate are technically polyphosphates, the polyphosphatesdesired are those having around four or more phosphate molecules so thatsurface adsorption at effective concentrations produces sufficientnon-bound phosphate functions which enhance the anionic surface chargeas well as hydrophilic character of the surfaces. The pyrophosphates arediscussed separately under additional anticalculus agents. The inorganicpolyphosphate salts desired include tetrapolyphosphate andhexametaphosphate, among others. Polyphosphates larger thantetrapolyphosphate usually occur as amorphous glassy materials. Thepresent invention may use linear “glassy” polyphosphates having theformula:

XO(XPO₃)_(n)X

wherein X is sodium or potassium and n averages from about 6 to about125. Polyphosphates manufactured by FMC Corporation, Philadelphia, Pa.,which are commercially known as Sodaphos (n≈6), Hexaphos (n≈13), andGlass H (n≈21) can be used. In certain embodiments thepolyphosphate-Glass H can be used. These polyphosphates may be usedalone or in a combination thereof.

The amount of the polymeric anti-tartar, anti-stain agent in certainembodiments may be from about 1% to about 35%, from about 2% to about30%, from about 5% to about 25%, or from about 6% to about 20%, byweight of the total oral composition.

The compositions herein may contain from about 0.025% to about 9%, byweight of the composition, of a surfactant. The compositions may containfrom about 0.5% to about 7%, alternatively from about 0.1% to about 5%,by weight of the composition, of the surfactant. In one embodiment, thesurfactant is selected from nonionic surfactants, anionic surfactants,cationic surfactants, and mixtures thereof. In another embodiment, thesurfactant is sodium lauryl sulfate.

In certain embodiments, the surfactant may be selected from anionic,nonionic, amphoteric, zwitterionic, cationic, or combinations thereof.

Examples of suitable surfactants for use herein include those that arereasonably stable and foam throughout a wide pH range. The surfactantmay be anionic, nonionic, amphoteric, zwitterionic, cationic, ormixtures thereof. Anionic surfactants useful herein include thewater-soluble salts of alkyl sulfates having from 8 to 20 carbon atomsin the alkyl radical (e.g., sodium alkyl sulfate) and the water-solublesalts of sulfonated monoglycerides of fatty acids having from 8 to 20carbon atoms. Sodium lauryl sulfate and sodium coconut monoglyceridesulfonates are examples of anionic surfactants of this type. Othersuitable anionic surfactants are sarcosinates, such as sodium lauroylsarcosinate, taurates, sodium lauryl sulfoacetate, sodium lauroylisethionate, sodium laureth carboxylate, and sodium dodecylbenzenesulfonate. Mixtures of anionic surfactants can also be employed.Many suitable anionic surfactants are disclosed by Agricola et al., U.S.Pat. No. 3,959,458, issued May 25, 1976.

Anionic surfactants useful herein include, for example, thewater-soluble salts of alkyl sulfates having from 8 to 20 carbon atomsin the alkyl radical (e.g., sodium alkyl sulfate) and the water-solublesalts of sulfonated monoglycerides of fatty acids having from 8 to 20carbon atoms. Sodium lauryl sulfate (SLS) and sodium coconutmonoglyceride sulfonates are examples of anionic surfactants of thistype. Other suitable anionic surfactants include sarcosinates, such assodium lauroyl sarcosinate, taurates, sodium lauryl sulfoacetate, sodiumlauroyl isethionate, sodium laureth carboxylate, and sodium dodecylbenzenesulfonate. Combinations of anionic surfactants can also beemployed. Many suitable anionic surfactants are disclosed by Agricola etal., U.S. Pat. No. 3,959,458.

Another class of anionic surfactants useful here are alkyl phosphates.The surface active organophosphate agents have a strong affinity forenamel surface and have sufficient surface binding propensity to desorbpellicle proteins and remain affixed to enamel surfaces. Suitableexamples of organophosphate compounds include mono-, di- or triestersrepresented by the general structure below wherein Z1, Z2, or Z3 may beidentical or different, at least one being an organic moiety, in oneembodiment selected from linear or branched, alkyl or alkenyl group offrom 1 to 22 carbon atoms, optionally substituted by one or morephosphate groups; alkoxylated alkyl or alkenyl, (poly)saccharide, polyolor polyether group.

Some other agents include alkyl or alkenyl phosphate esters representedby the following structure:

wherein R1 represents a linear or branched, alkyl or alkenyl group offrom 6 to 22 carbon atoms, optionally substituted by one or morephosphate groups; n and m, are individually and separately, 2 to 4, anda and b, individually and separately, are 0 to 20; Z2 and Z3 may beidentical or different, each represents hydrogen, alkali metal,ammonium, protonated alkyl amine or protonated functional alkyl aminesuch as an alkanolamine, or a R1-(OCnH2n)a(OCmH2m)b-group. Examples ofsuitable agents include alkyl and alkyl(poly)alkoxy phosphates such aslauryl phosphate; PPG5 ceteareth-10 phosphate; Laureth-1 phosphate;Laureth-3 phosphate; Laureth-9 phosphate; Trilaureth-4 phosphate; C12-18PEG 9 phosphate; Sodium dilaureth-10 phosphate. In one embodiment, thealkyl phosphate is polymeric. Examples of polymeric alkyl phosphatesinclude those containing repeating alkoxy groups as the polymericportion, in particular 3 or more ethoxy, propoxy isopropoxy or butoxygroups.

Additional suitable polymeric organophosphate agents include dextranphosphate, polyglucoside phosphate, alkyl polyglucoside phosphate,polyglyceryl phosphate, alkyl polyglyceryl phosphate, polyetherphosphates and alkoxylated polyol phosphates. Some specific examples arePEG phosphate, PPG phosphate, alkyl PPG phosphate, PEG/PPG phosphate,alkyl PEG/PPG phosphate, PEG/PPG/PEG phosphate, dipropylene glycolphosphate, PEG glyceryl phosphate, PBG (polybutylene glycol) phosphate,PEG cyclodextrin phosphate, PEG sorbitan phosphate, PEG alkyl sorbitanphosphate, and PEG methyl glucoside phosphate. Suitable non-polymericphosphates include alkyl mono glyceride phosphate, alkyl sorbitanphosphate, alkyl methyl glucoside phosphate, alkyl sucrose phosphates.

Another suitable surfactant is one selected from sarcosinatesurfactants, isethionate surfactants and taurate surfactants. In oneembodiment, an alkali metal or ammonium salts of these surfactants areused. Examples of those sodium and potassium salts include following:lauroyl sarcosinate, myristoyl sarcosinate, palmitoyl sarcosinate,stearoyl sarcosinate and oleoyl sarcosinate, or combinations thereof. Ofthese anionic surfactants, examples of some which provide an unwantedtaste within an oral care composition include, for example, SLS, lauroylsarcosinate, and/or fatty alcohols or acids associated with naturalbased surfactants. The unwanted tastes often associated with thesesurfactants are soapy, chemical, and/or artificial.

The amphoteric surfactants useful in the present invention can bebroadly described as derivatives of aliphatic secondary and tertiaryamines in which the aliphatic radical can be a straight chain orbranched and wherein one of the aliphatic substituents contains fromabout 8 to about 18 carbon atoms and one contains an anionicwater-solubilizing group, e.g., carboxylate, sulfonate, sulfate,phosphate, or phosphonate. Other suitable amphoteric surfactants arebetaines, specifically cocamidopropyl betaine. Mixtures of amphotericsurfactants can also be employed. Many of these suitable nonionic andamphoteric surfactants are disclosed by Gieske et al., U.S. Pat. No.4,051,234, issued Sep. 27, 1977. Zwitterionic or amphoteric surfactantsuseful in oral care compositions include derivatives of aliphaticquaternary ammonium, phosphonium, and sulfonium compounds, in which thealiphatic radicals can be straight chain or branched, and one of thealiphatic substituents contains from about 8 to 18 carbon atoms and onecontains an anionic water-solubilizing group, e.g., carboxy, sulfonate,sulfate, phosphate or phosphonate. Suitable betaine surfactants aredisclosed in U.S. Pat. No. 5,180,577 to Polefka et al. Typical alkyldimethyl betaines include decyl betaine or2-(N-decyl-N,N-dimethylammonio)acetate, coco betaine or 2-(N-coco-N,N-dimethyl ammonio)acetate, myristyl betaine, palmityl betaine, laurylbetaine, cetyl betaine, cetyl betaine, stearyl betaine, etc. Theamidobetaines are exemplified by cocoamidoethyl betaine, cocoamidopropylbetaine (CADB), and lauramidopropyl betaine. Of these surfactants,examples of some which provide an unwanted taste within an oral carecomposition include, for example, cocoamidopropyl betaine and laurylbetaine. The unwanted tastes often associated with these types ofsurfactants are soapy and chemical. These surfactants are generallyincluded in an oral care composition in a range of about 0.5% to about5%.

Cationic surfactants useful in the present invention include, forexample, derivatives of quaternary ammonium compounds having one longalkyl chain containing from about 8 to 18 carbon atoms such as lauryltrimethylammonium chloride; cetyl pyridinium chloride; cetyltrimethylammonium bromide; coconut alkyltrimethylammonium nitrite; cetylpyridinium fluoride or combinations thereof. Additional quaternaryammonium fluorides having detergent properties are described in U.S.Pat. No. 3,535,421 to Briner et al.

Nonionic surfactants which can be used in the compositions of thepresent invention can be broadly defined as compounds produced by thecondensation of alkylene oxide groups (hydrophilic in nature) with anorganic hydrophobic compound which may be aliphatic or alkyl-aromatic innature. Examples of suitable nonionic surfactants include poloxamers(sold under trade name PLURONIC), polyoxyethylene, polyoxyethylenesorbitan esters (sold under trade name TWEENS), Polyoxyl 40 hydrogenatedcastor oil, fatty alcohol ethoxylates, polyethylene oxide condensates ofalkyl phenols, products derived from the condensation of ethylene oxidewith the reaction product of propylene oxide and ethylene diamine,ethylene oxide condensates of aliphatic alcohols, long chain tertiaryamine oxides, long chain tertiary phosphine oxides, long chain dialkylsulfoxides, and mixtures of such materials.

The compositions herein may have a total solids content of 50% or less,by weight of the composition. In certain embodiments, the compositionsmay have total solids content of 40% or less. The total solid contentincludes the abrasives used herein.

The compositions herein may contain from about 5% to about 12%, byweight of the composition, of water. The amount of water refers to thetotal amount of free water available in the composition and may be addeddirectly as water or may be added indirectly as a solvent or carrier foranother material or naturally contained in the material.

The water activity value of the compositions of the present inventionmay be from about 0.25 to about 0.46 measured at about 22° C. As usedherein, “water activity” refers to the equilibrium relative humidity orpartial vapor pressure of the air above a product sample in a closedsystem divided by the relative humidity of air above pure water at thesame temperature. Water activity can be expressed as % equilibriumrelative humidity (% ERH) or A_(w). % ERH=100×A_(w). The compositionsherein may have a water activity value of from about 0.25 to about 0.46.

Without being limited by theory, it is believed water activity is animportant property of topical compositions such as oral carecompositions including dentifrice. Water activity can affect ingredientsolubility which in turn can be used to modify product rheology.Formulas that contain the same total concentration of water can havewater activity values that differ dramatically depending on thehygroscopic characteristics of the other ingredients in the formula.Nearly all dentifrice paste or gel semi-solid formulations usepolyhydric alcohols to help limit water loss over the self life of theproduct. Many polyhydric alcohols are classified as humectants and themost commonly used humectant materials in dentifrice formulations areglycerin, sorbitol, propylene glycol, polyethylene glycols and mixturesthereof. Other polyhydric alcohols can be used and frequently a blend ofhumectants is used to optimize cost, aesthetics, as well as,manufacturing requirements and other considerations.

Water activity may be measured using a ROTRONIC HYGROLAB 3, fromRotronic Instrument Corp., Hauppauge, N.Y., water activity instrument.Information is readily available from the manufacture as to therecommended calibration, sample preparation and other factors that needto be considered to assure measurement accuracy. An important variableto control in making a water activity measurement is temperature.Relative humidity or partial pressure of the water vapor is stronglydependent on temperature and therefore accuracy of the temperaturecontrol and measurement is an important component in reporting wateractivity data.

Further, without being limited by theory, in addition to humectants andwater, other materials can affect the water activity of a composition.Other materials that may affect the water activity value include salts.However, generally varying the level of humectants is more efficient andpractical for topical formulations. Each humectant has an individualcapacity to affect water activity with glycerin being the mosteffective. By combining humectants and adjusting the free water added toa formulation the same water activity value can be achieved using avariety of different formulas. Although modeling can be done to developthe relationship of water activity to a particular formulation designspace, direct measurement using a water activity meter is often morepractical since the measurement can be done in a matter of minutes usingany of the various water activity meters commercially available.

The compositions herein may contain at least 0.25%, by weight of thecomposition, of an oral care component.

In one embodiment, the oral care component is selected from stannouschloride, triclosan, zinc lactate, zinc oxide, zinc citrate, andmixtures thereof. In one embodiment, the composition contains from about0.25% to about 3% stannous chloride. In one embodiment, the oral carecomponent is zinc citrate.

In one embodiment, the oral care compositions contain from about 0.25%to about 8%, by weight of the composition of at least one oral carecomponent selected from metal salts, antimicrobial agents, bad breathreduction agents, bleaching agents, or a combination thereof. In oneembodiment, the oral care composition comprises from about 0.025% toabout 7%, alternatively from about 0.25% to about 5%, by weight of thecomposition, of the oral care component.

The compositions may further include additional oral care component,discussed below as “optional oral care components”. Such oral carecomponents are generally present in an amount of about 0.0001% to about8%, by weight of the composition.

Metal salts have a wide range of functions from antimicrobial agents tosensitivity agents and/or buffers. In one embodiment, the metal saltcomprises a zinc salt, stannous salt, potassium salt, copper salt, or acombination thereof.

In one embodiment, the zinc salt is selected from zinc fluoride, zincchloride, zinc iodide, zinc chlorofluoride, zinc actetate, zinchexafluorozirconate, zinc sulfate, zinc lactate, zinc tartrate, zincgluconate, zinc citrate, zinc malate, zinc glycinate, zincpyrophosphate, zinc metaphosphate, zinc oxalate, zinc phosphate, zinccarbonate, and combinations thereof. In another embodiment, the zincsalt is selected from zinc chloride, zinc citrate, zinc gluconate, zinclactate, zinc oxide, and combinations thereof.

In one embodiment, the potassium salt is selected from potassiumnitrate, potassium citrate, potassium oxalate, potassium bicarbonate,potassium acetate, potassium chloride, and combinations thereof.

In one embodiment, the copper salt is selected from copper fluoride,copper chloride, copper iodide, copper chlorofluoride, copper actetate,copper hexafluorozirconate, copper sulfate, copper lactate, coppertartrate, copper gluconate, copper citrate, copper malate, copperglycinate, copper pyrophosphate, copper metaphosphate, copper oxalate,copper phosphate, copper carbonate, and combinations thereof. In afurther embodiment, the copper salt is selected from copper gluconate,copper acetate, copper glycinate, and combinations thereof.

In another embodiment, the stannous salt is selected from stannousfluoride, stannous chloride, stannous iodide, stannous chlorofluoride,stannous actetate, stannous hexafluorozirconate, stannous sulfate,stannous lactate, stannous tartrate, stannous gluconate, stannouscitrate, stannous malate, stannous glycinate, stannous pyrophosphate,stannous metaphosphate, stannous oxalate, stannous phosphate, stannouscarbonate, and combinations thereof. In a further embodiment, thestannous salt is selected from stannous fluoride, stannous chloride,stannous chloride dihydrate, stannous fluoride, stannous lactate,stannous gluconate, stannous sulfate, and combinations thereof.

Dentifrices containing stannous salts, particularly stannous fluorideand stannous chloride, are described in U.S. Pat. No. 5,004,597 toMajeti et al. Other descriptions of stannous salts are found in U.S.Pat. No. 5,578,293 issued to Prencipe et al. and in U.S. Pat. No.5,281,410 issued to Lukacovic et al. In addition to the stannous ionsource, other ingredients needed to stabilize the stannous may beincluded, such as the ingredients described in Majeti et al. andPrencipe et al.

One example of an antimicrobial agent useful herein is a quaternaryammonium compound. Those useful herein include, for example, those inwhich one or two of the substitutes on the quaternary nitrogen has acarbon chain length (typically alkyl group) from about 8 to about 20,typically from about 10 to about 18 carbon atoms while the remainingsubstitutes (typically alkyl or benzyl group) have a lower number ofcarbon atoms, such as from about 1 to about 7 carbon atoms, typicallymethyl or ethyl groups. Dodecyl trimethyl ammonium bromide,tetradecylpyridinium chloride, domiphen bromide, N-tetradecyl-4-ethylpyridinium chloride, dodecyl dimethyl(2-phenoxyethyl) ammonium bromide,benzyl dimethoylstearyl ammonium chloride, cetylpyridinium chloride,quaternized 5-amino-1,3-bis(2-ethyl-hexyl)-5-methyl hexahydropyrimidine,benzalkonium chloride, benzethonium chloride and methyl benzethoniumchloride are exemplary of typical quaternary ammonium antibacterialagents.

Other compounds include bis[4-(R-amino)-1-pyridinium]alkanes asdisclosed in U.S. Pat. No. 4,206,215, Jun. 3, 1980, to Bailey. Otherquaternary ammonium compounds include the pyridinium compounds. Examplesof pyridinium quaternary ammonium compounds include cetylpyridinium andtetradecylpyridinium halide salts (i.e., chloride, bromide, fluoride andiodide).

The oral care compositions of the present invention may also includeother antimicrobial agents including non-cationic antimicrobial agentssuch as halogenated diphenyl ethers, phenolic compounds including phenoland its homologs, mono and poly-alkyl and aromatic halophenols,resorcinol and its derivatives, xylitol, bisphenolic compounds andhalogenated salicylanilides, benzoic esters, and halogenatedcarbanilides. Also useful antimicrobials are enzymes, includingendoglycosidase, papain, dextranase, mutanase, and combinations thereof.Such agents are disclosed in U.S. Pat. No. 2,946,725, Jul. 26, 1960, toNorris et al. and in U.S. Pat. No. 4,051,234 to Gieske et al. Examplesof other antimicrobial agents include chlorhexidine, triclosan,triclosan monophosphate, and flavor oils such as thymol. Triclosan andother agents of this type are disclosed in Parran, Jr. et al., U.S. Pat.No. 5,015,466, and U.S. Pat. No. 4,894,220 to Nabi et al.

The compositions of the present invention may contain from about 0.01%to about 4.0%, by weight of the composition, of an oral care componentselected from bad breath reduction agents. These agents generally workto reduce breath malodor.

Examples of bad breath reduction agents include copper salts andcarbonyl compounds such as ascorbic acid [3-oxo-L-gulofuranolactone];cis-jasmone[3-methyl-2-(2-pentenyl-2-cyclopentenone];2,5-dimethyl-4-hydroxy-3(2H)-furanone;5-ethyl-3-hydroxy-4-methyl-2(5H)-furanone;vanillin[3-hydroxy-3-methoxybenzaldehyde]; ethyl vanillin;anisaldehyde[4-methoxybenzaldehyde]; 3,4-methylenedioxybenzaldehyde;3,4-dimethoxybenzaldehyde; 4-hydroxybenzaldehyde; 2-methoxybenzaldehyde;benzaldehyde; cinnamaldehyde[3-phenyl-2-propenal]; hexyl cinnamaldehyde;α-methyl cinnamaldehyde; ortho-methoxy cinnamaldehyde; citral; linalool;geraniol; eugenol; or combinations thereof.

The compositions of the present invention may contain from about 0.01%to about 30%, from about 0.1% to about 10%, or from about 0.5% to about5%, by weight of the composition, of an oral care component selectedfrom bleaching agents. Bleaching agents are generally agents whichwhiten teeth.

Examples of bleaching agents include peroxides, perborates,percarbonates, peroxyacids, persulfates, and combinations thereof.Suitable peroxide compounds include hydrogen peroxide, urea peroxide,calcium peroxide, sodium peroxide, zinc peroxide, or combinationsthereof. One example of a percarbonate is sodium percarbonate. Anexample of a persulfate includes oxones.

The compositions of the present invention may also contain from about0.0001% to about 8% or from about 0.001% to about 5%, by weight of thecomposition, of an optional oral care component. Optional oral carecomponents include flavors, anti-tartar agents, colorants, sensates,sweeteners, anti-calculus agents, anti-staining agents and combinationsthereof.

In one embodiment, the composition further includes a flavoring agent,or mixtures thereof. Examples of some flavoring agents useful hereininclude mint oils, wintergreen, clove bud oil, cassia, sage, parsleyoil, marjoram, lemon, orange, propenyl guaethol, heliotropine,4-cis-heptenal, diacetyl, methyl-p-tert-butyl phenyl acetate, methylsalicylate, ethyl salicylate, 1-menthyl acetate, oxanone, α-irisone,methyl cinnamate, ethyl cinnamate, butyl cinnamate, ethyl butyrate,ethyl acetate, methyl anthranilate, iso-amyl acetate, iso-amyl butyrate,allyl caproate, eugenol, eucalyptol, thymol, cinnamic alcohol, octanol,octanal, decanol, decanal, phenylethyl alcohol, benzyl alcohol,α-terpineol, linalool, limonene, citral, neral, geranial, geraniolnerol, maltol, ethyl maltol, anethole, dihydroanethole, carvone,menthone, β-damascenone, ionone, γ-decalactone, γ-nonalactone,γ-undecalactone, or combinations thereof. In one embodiment, theflavoring agent is selected from oil of wintergreen, oil of peppermint,oil of spearmint, clove bud oil, menthol, anethole, methyl salicylate,eucalyptol, cassia, 1-menthyl acetate, sage, eugenol, parsley oil,oxanone, alpha-irisone, marjoram, lemon, orange, propenyl guaethol,cinnamon, vanillin, ethyl vanillin, heliotropine, 4-cis-heptenal,diacetyl, methyl-para-tert-butyl phenyl acetate, and mixtures thereof.

One example of an antitartar agent is a pyrophosphate salt as a sourceof pyrophosphate ion. The pyrophosphate salts useful in the presentcompositions include, for example, the mono-, di- and tetraalkali metalpyrophosphate salts and combinations thereof. Disodium dihydrogenpyrophosphate (Na2H2P2O7), sodium acid pyrophosphate, tetrasodiumpyrophosphate (Na4P2O7), and tetrapotassium pyrophosphate (K4P207) intheir unhydrated as well as hydrated forms are further species.

The compositions herein may include a coloring agent. The coloring agentmay be in the form of an aqueous solution, preferably 1% coloring agentin a solution of water. In one embodiment, the composition contains fromabout 0.01% to about 5%, by weight of the coloring solution.

Examples of coloring agents useful herein include D&C Yellow No. 10,FD&C Blue No. 1, FD&C Red No. 40, D&C Red No. 33 and combinationsthereof. In one embodiment, the composition comprises from about 0.0001%to about 0.1%, alternatively from about 0.001% to about 0.01%, by weightof the oral care composition, of a colorant.

Sensate molecules such as cooling, warming, and tingling agents areuseful to deliver signals to the consumer. The most well-known coolingsensate compound is menthol, particularly 1-menthol, which is foundnaturally in peppermint oil. Other isomers of menthol (neomenthol,isomenthol and neoisomenthol) have somewhat similar, but not identicalodor and taste, i.e., having disagreeable notes described as earthy,camphor, musty, etc.

Among synthetic coolants, many are derivatives of or are structurallyrelated to menthol, i.e., containing the cyclohexane moiety, andderivatized with functional groups including carboxamide, ketal, ester,ether and alcohol. Examples include the p-menthanecarboxamide compoundssuch as N-ethyl-p-menthan-3-carboxamide, known commercially as “WS-3”,and others in the series such as WS-5(N-ethoxycarbonylmethyl-p-menthan-3-carboxamide), WS-12[N-(4-methoxyphenyl)-p-menthan-3-carboxamide] and WS-14(N-tert-butyl-p-menthan-3-carboxamide). Examples of menthane carboxyesters include WS-4 and WS-30. An example of a synthetic carboxamidecoolant that is structurally unrelated to menthol isN,2,3-trimethyl-2-isopropylbutanamide, known as “WS-23”. Additionalexamples of synthetic coolants include alcohol derivatives such as3-(1-menthoxy)-propane-1,2-diol known as TK-10, isopulegol (under thetradename Coolact P) and p-menthane-3,8-diol (under the tradenameCoolact 38D) all available from Takasago; menthone glycerol acetal knownas MGA; menthyl esters such as menthyl acetate, menthyl acetoacetate,menthyl lactate known as Frescolat® supplied by Haarmann and Reimer, andmonomenthyl succinate under the tradename Physcool from V. Mane. TK-10is described in U.S. Pat. No. 4,459,425 to Amano et al. Other alcoholand ether derivatives of menthol are described e.g., in GB 1,315,626 andin U.S. Pat. Nos. 4,029,759; 5,608,119; and 6,956,139. WS-3 and othercarboxamide cooling agents are described for example in U.S. Pat. Nos.4,136,163; 4,150,052; 4,153,679; 4,157,384; 4,178,459 and 4,230,688.Additional N-substituted p-menthane carboxamides are described in WO2005/049553A1 including N-(4-cyanomethylphenyl)-p-menthanecarboxamide,N-(4-sulfamoylphenyl)-p-menthanecarboxamide,N-(4-cyanophenyl)p-menthanecarboxamide,N-(4-acetylphenyl)-p-menthanecarboxamide,N-(4-hydroxymethylphenyl)-p-menthanecarboxamide andN-(3-hydroxy-4-methoxyphenyl)-p-menthanecarboxamide. Other N-substitutedp-menthane carboxamides include amino acid derivatives such as thosedisclosed in WO 2006/103401 and in U.S. Pat. Nos. 4,136,163; 4,178,459and 7,189,760 such asN-((5-methyl-2-(1-methylethyl)cyclohexyl)carbonyl)glycine ethyl esterand N-((5-methyl-2-(1-methylethyl)cyclohexyl)carbonyl)alanine ethylester. Menthyl esters including those of amino acids such as glycine andalanine are disclosed e.g., in EP 310,299 and in U.S. Pat. Nos.3,111,127; 3,917,613; 3,991,178; 5,703,123; 5,725,865; 5,843,466;6,365,215; 6,451,844; and 6,884,903. Ketal derivatives are described,e.g., in U.S. Pat. Nos. 5,266,592; 5,977,166 and 5,451,404. Additionalagents that are structurally unrelated to menthol but have been reportedto have a similar physiological cooling effect include alpha-ketoenamine derivatives described in U.S. Pat. No. 6,592,884 including3-methyl-2-(1-pyrrolidinyl)-2-cyclopenten-1-one (3-MPC),5-methyl-2-(1-pyrrolidinyl)-2-cyclopenten-1-one (5-MPC), and2,5-dimethyl-4-(1-pyrrolidinyl)-3(2H)-furanone (DMPF); icilin (alsoknown as AG-3-5, chemical name1-[2-hydroxyphenyl]-4-[2-nitrophenyl]-1,2,3,6-tetrahydropyrimidine-2-one)described in Wei et al., J. Pharm. Pharmacol. (1983), 35:110-112.

Some examples of warming sensates include ethanol; capsicum; nicotinateesters, such as benzyl nicotinate; polyhydric alcohols; capsicum powder;a capsicum tincture; capsicum extract; capsaicin; homocapsaicin;homodihydrocapsaicin; nonanoyl vanillyl amide; nonanoic acid vanillylether; vanillyl alcohol alkyl ether derivatives such as vanillyl ethylether, vanillyl butyl ether, vanillyl pentyl ether, and vanillyl hexylether; isovanillyl alcohol alkyl ethers; ethylvanillyl alcohol alkylethers; veratryl alcohol derivatives; substituted benzyl alcoholderivatives; substituted benzyl alcohol alkyl ethers; vanillin propyleneglycol acetal; ethylvanillin propylene glycol acetal; ginger extract;ginger oil; gingerol; zingerone; or combinations thereof.

Sweetening agents can be added to the compositions. Examples ofsweetening agents useful herein include saccharin, dextrose, sucrose,lactose, xylitol, maltose, levulose, aspartame, sodium cyclamate,D-tryptophan, dihydrochalcones, acesulfame, and mixtures thereof. In oneembodiment, the composition contains from about 0.005% to about 5%, byweight of the composition, of a sweetening agent

Examples of sweetening agents useful herein include those selected fromsaccharin, chloro-sucrose (sucralose), steviolglycosides, rebaudiosideA, rebaudioside B, rebaudioside C, rebaudioside D, rebaudioside E,rebaudioside F, dulcoside A, dulcoside B, rubusoside, stevia,stevioside, acesulfame K, xylitol, neohesperidine DC, alitame,aspartame, neotame, alitame, thaumatin, cyclamate, glycyrrhizin,mogroside IV, mogroside V, Luo Han Guo sweetener, siamenoside, monatinand its salts (monatin SS, RR, RS, SR), curculin, monellin, mabinlin,brazzein, hemandulcin, phyllodulcin, glycyphyllin, phloridzin,trilobatin, baiyanoside, osladin, polypodoside A, pterocaryoside A,pterocaryoside B, mukurozioside, phlomisoside I, periandrin I,abrusoside A, cyclocarioside I,N—[N-[3-(3-hydroxy-4-methoxyphenyl)propyl]-L-α-aspartyl]-L-phenylalanine1-methyl ester,N—[N-[3-(3-hydroxy-4-methoxyphenyl)-3-methylbutyl]-L-α-aspartyl]-L-phenylalanine1-methyl ester,N—[N-[3-(3-methoxy-4-hydroxyphenyl)propyl]-L-α-aspartyl]-L-phenylalanine1-methyl ester, salts thereof, and combinations thereof.

In one embodiment, the sweetening agent is selected from, REBIANA, NHDC,acesulfame K, and combinations thereof. Additionally, a flavor enhancersuch as glucono-δ-lactone can be added to the composition.

Anticalculus agents useful herein include materials known to beeffective in reducing calcium phosphate mineral deposition related tocalculus formation. Examples include pyrophosphates, tripolyphosphates,synthetic anionic polymers[including polyacrylates and copolymers ofmaleic anhydride or acid and methyl vinyl ether (e.g., Gantrez), asdescribed, for example, in U.S. Pat. No. 4,627,977 to Gaffar et al.; aswell as, e.g., polyamino propane sulfonic acid (AMPS)], zinc citratetrihydrate, diphosphonates (e.g., EHDP; AHP), polypeptides (such aspolyaspartic and polyglutamic acids), and mixtures thereof.

The compositions herein may include a stain-reducing agent. Suchstain-reducing agent may be particularly desirable for compositions thatcontain stannous ions. Examples of stain-reducing agents useful hereininclude PLASDONE S-630 (Ashland Specialty Ingredients, Wayne, N.J.) oraluminum hydrate may further be added to the composition. PLASDONE ispolyvinyl pyrrolidone (PVP) that can be synthesized by polymerizingvinylpyrrolidone. Commercially, it has been produced as a series ofproducts having mean molecular weights ranging from 10,000 to 700,000.Herein, the low molecular weights and middle molecular weights (fromabout 10,000 to about 100,000) are preferred. In order to remove staineffectively, the level of PVP is preferably from about 0.5% to about10%, more preferably from about 1.0% to about 7.0%, and even morepreferably from about 1.5% to about 5.0%.

The compositions herein typically have a pH of from about 4 to about 10.In one embodiment, the pH is from about 4.5 to about 9, alternativelyfrom about 5.5 to about 7. In one embodiment, the pH of the compositionis measured within one hour of the final product being formed. Inanother embodiment, the pH of the composition is the neat pH, beforepackaging.

The compositions herein may include a pH modifier to obtain thedesirable pH.

In certain embodiments, the composition further contains less than about1%, by weight of the composition, of clay particles.

The compositions of the present invention may contain titanium dioxide.Titanium dioxide is a white powder which adds opacity to thecompositions. In certain embodiments, the composition contains titaniumdioxide from about 0.25% to about 5%, from about 0.25% to about 2.5%, orfrom about 0.25% to 1.5%, by weight of the composition.

Examples 1A-1D Dentifrice Compositions

Dentifrice compositions according to the present invention are shown inExamples 1A, 1B, 1C, and 1D, below alongside a comparative formulation.All of the dentifrice formulations are made by traditional means andprocesses. Compositions 1A-1D exhibit improved rheology and stand-upversus the comparative example.

Comparative INGREDIENT Formula 1A 1B 1C 1D Glycerin 34 31 44 32.25 29Water 2.9 0.23 1.016 7.49 Propylene Glycol 10.0 6.5 6.0 8.0 7.5 PEG 66.0 7.0 7.0 PEG 12 6.0 PEG 4000 2.1 1.0 0.5 3.8 PLURIOL E 4000 Pastille*PEG 8000 2.0 PLURIOL E 8000 NF Prill* Stannous Fluoride 0.45 0.45 0.450.45 0.45 Zinc Lactate 2.0 1.5 2.3 2.7 3.0 Sodium Gluconate 0.5 1.0 0.750.50 0.66 Sodium Saccharin 0.5 0.25 0.4 0.5 0.4 Trisodium 1.25 1.0 1.01.1 1.0 Phosphate Sodium 15.0 13.0 12.5 14.0 13.0 PolyphosphateParticles Precipitated Silica 24.0 13.0 13.0 15.0 12.5 ZEODENT 119**Precipitated Silica 13.0 12.0 10.0 12.5 ZEODENT 109** PrecipitatedSilica 1.0 ZEODENT 165** Carrageenan 0.6 0.15 0.30 0.40 .22 Hydroxyethyl.30 Cellulose Xanthan Gum 0.30 0.1 0.12 0.2 0.08 Titanium Dioxide 1.00.1 Sodium Lauryl 3.5 3.0 4.0 3.0 Sulfate Solution (27.9%) Poloxamer 4070.5 1.0 Flavor 1.3 1.25 1.15 1.0 1.0 Color Solution 0.300 0.300 0.3000.084 Polyethylene 0.3 0.5 0.3 microwhite specks TOTAL 100 100 100 100100 *PEG 4000 PLURIOL E 4000 Pastille and PEG 8000 PLURIOL E 8000 NFPrill are polyethylene glycol materials having an average molecularweight of 4000 and 8000, respectively and are commercially availablefrom BASF (Florham Park, New Jersey, USA. **Precipitated Silicas ZEODENT119, ZEODENT 109 and ZEODENT 165 are all precipitated silicascommercially available from Huber (Havre de Grace, Maryland, USA).

The dimensions and values disclosed herein are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each such dimension is intended to mean boththe recited value and a functionally equivalent range surrounding thatvalue. For example, a dimension disclosed as “40 mm” is intended to mean“about 40 mm”

Except as otherwise noted, the articles “a”, “an”, and “the” mean “oneor more”.

As used herein, “contain” or “comprising” means that other steps andother ingredients which do not affect the end result can be added. Thisterm encompasses the terms “consisting of” and “consisting essentiallyof”. The compositions and methods/processes of the present invention cancontain, include, comprise, consist of, and consist essentially of theelements and limitations of the invention described herein, as well asany of the additional or optional ingredients, components, steps, orlimitations described herein.

Every document cited herein, including any cross referenced or relatedpatent or application, is hereby incorporated herein by reference in itsentirety unless expressly excluded or otherwise limited. The citation ofany document is not an admission that it is prior art with respect toany invention disclosed or claimed herein or that it alone, or in anycombination with any other reference or references, teaches, suggests ordiscloses any such invention. Further, to the extent that any meaning ordefinition of a term in this document conflicts with any meaning ordefinition of the same term in a document incorporated by reference, themeaning or definition assigned to that term in this document shallgovern.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

What is claimed is:
 1. A dentifrice composition comprising: a. apolyethylene glycol having an average molecular weight of from about3,000 to about 8,000; b. from about 29% to about 44%, by weight of thecomposition, glycerin; c. a precipitated silica; d. a fluoride sourceselected from the group consisting of stannous fluoride, sodiumfluoride, sodium monofluorophosphate, and mixtures thereof; wherein thepolyethylene glycol forms a crystalline structure in the composition andwherein the composition has a water activity from about 0.25 to about0.46 measured at about 22° C.
 2. The dentifrice composition of claim 1further comprising from about 0.25% to about 7%, by weight of thecomposition, polyethylene glycol.
 3. The dentifrice composition of claim1 further comprising from about 0.5% to about 4%, by weight of thecomposition, polyethylene glycol.
 4. The dentifrice composition of claim1 wherein the polyethylene has an average molecular weight of from about3,000 to about 6,000.
 5. The dentifrice composition of claim 1 whereinthe polyethylene has an average molecular weight of from about 3,500 toabout 5,500
 6. The dentifrice composition of claim 1 further comprisingsodium pyrophosphate.
 7. The dentifrice composition of claim 1 furthercomprising a low molecular weight polyethylene glycol.
 8. The dentifricecomposition of claim 1 further comprising propylene glycol.
 9. Thedentifrice composition of claim 1 further comprising from about 0.1% toabout 5%, by weight of the composition, sodium lauryl sulfate.
 10. Thedentifrice composition of claim 1 further comprising a color and aflavor.
 11. The dentifrice composition of claim 1 further comprisingfrom about 5% to about 12%, by weight of the composition, water.
 12. Amethod of making the dentifrice composition of claim 1 wherein thepolyethylene glycol is added to the composition in solution with solventor is added in a controlled manner as a molten material to thecomposition at a temperature less than about 35° C. and with turbulentmixing or vigorous agitation.
 13. A dentifrice composition comprising:a. a poloxamer; b. from about 29% to about 44%, by weight of thecomposition, glycerin; c. a precipitated silica; d. a fluoride sourceselected from the group consisting of stannous fluoride, sodiumfluoride, sodium monofluorophosphate, and mixtures thereof; wherein thepolyethylene glycol forms a crystalline structure in the composition andwherein the composition has a water activity from about 0.25 to about0.46 measured at about 22° C.
 14. The dentifrice composition of claim 13comprising greater than about 0.05% poloxamer.
 15. The dentifricecomposition of claim 13 comprising greater than about 0.1% poloxamer.16. The dentifrice composition of claim 13 further comprising from about0% to about 1.5% by weight of the composition, of a viscosity modifierselected from gums, binders, cellulosic thickeners, and mixturesthereof.
 17. The dentifrice composition of claim 13 wherein thecomposition has a total solids content of 50% or less, by weight of thecomposition.
 18. The dentifrice composition of claim 13 furthercomprising from about 5% to about 12%, by weight of the composition,water.
 19. The dentifrice composition of claim 13 wherein theprecipitated silica has an oil absorption of less than about 250 cc/100g, a BET surface area of less than about 150 m2/g, and a median particlesize of less than about 50 microns.